Improvement in the construction of the fire-chambers and in operating the fire of



J. REESE.

Furnace.

Patented Feb. 5, 1861.

iron.

UNITED STATES A lENT rrrcE.

JACOB REESE, OF PITTSBURG, PENNSYLVANIA.

IMPROVEMENT IN THE CONSTRUCTION OF THE FIRE-CHAMBERS AND IN OPERATINGTHE FIRE 0F REVERBERATORY FURNACES.

Specification forming part of Letters Patent No. 31,327, dated February5, 1861.

T 0 a whom it may concern;

Be it known that I, JACOB REEsE, of the city of Pittsburg, in the countyof Allegheny and State of Pennsylvania, have invented a new and usefulImprovement in the Fire- 'Chambers of Furnaces for Puddling, Boiling, orReheating Iron, in which Goal is used as a Fuel; and I do hereby declarethe following to be a full, clear, and exact description thereof,reference being had to the annexed drawings, forming part of thisspecificalion, which repre sent the application of my improvement to theordinary puddling-furnaces for the manufacture of iron.

It is well-known that coal ordinarily used for fuel contains, besidesits combustible constituents, some that are incombustible, at least atthe degree of heat employed in most furnaces-such as'silica, alumina,and sulphate of These, not being removed in the process of combustion ofthe coal, form into hard cakes or lumps,which are caller clinkers, whichchoke up the fire, settle about the grate-bars, closing up the passageof the air into the fire,

, thus impeding the draft and causing a great loss of heat.

To obviate this difficulty it is necessary to stir the fire repeatedlyin order to free the air-passages between the grate-bars, and to removethe clinker, which fills up the grate without adding to the heat of thefurnace. This stirring of the fire in puddling and other furnaces isdone with long iron rods, which are pushed from beneath up between thebars of the grate, the effect of which is to bend and wear out thegrate-bars very rapidly,

and to cause a great loss of fuel by the escape between the bars of alarge quantity of partially-burned coal,which falls down with the ashesand clinker and is lost. Oftentimes the clinker accumulates so rapidlythat it is necessary to remove one or more of the grate-bars from thefurnace in order to get rid of it, and,

by the current of cold air passing upward into the fire, the meltedcinder is cooled and forms the clinker. The use of grate-bars orperforated plates for the bed of a furnace and the admission of theblast or draft of air through these grate-bars from below is the causeof the formation andaccumulation of clinker. It is also in a greatmeasure owing to the use of open grate-bars and the admission of thecold air through them into thefurnace that so large a quantity of smokeis evolved from these furnaces. My invention is designed to remedy boththese defects in puddling, boiling, and reheating furnaces where coal isconsumed as fuel, by causing the cinder, instead of forming clinker,'torun out of the furnace in a melted state; and also by the mode ofintroducing the blast or current of air to cause it to become heatedbefore it reaches the bituminous matter on the top of the firesufficiently to cause the combustion of the smoke. These importantresults I accomplish by constructing the fire-chamber of furnaces insuch a manner as to prevent the entrance of the air for the support ofcombustion from beneath the furnace-bottom, either by dispensing withgratebars entirely and using a closed bottom, or by closing up the spaceunder the grate-bars; and in either case introducing the blast orcurrent of air in any convenient way only at a point or points in thefire chamber sufficiently above the level of the furnace-bottom orgrate-bars, and constructing a hopper-shaped or contracted receptacle,of greater or less depth, below the point of entrance of the blast forthe collection of the cinder in a fused state,which is allowed to runoff spontaneously as it is formed and rises to the level of its exit. Bythis means the cinder is collected in a vitreous melted mass on the bedor bottom of the firechamber and forms a good protection to it, as thelower part of the cinder is comparatively cool. The coal is floated ontop of the melted cinder. The blast of air entering about the level ofthe surface of the melted cinder is heated as it passes over thissurface, and thence through the hottest and clearest part of the fire tothe top of the burning mass of coal,where it issufficiently hot toconsume the smoke.

To enable others skilled in the art to construct and use my improvement,I will proceed to describe it more fully in its practical application toa puddling-furnace, referring to the accompanying drawings, in which-Figure 1 is a perspective representation of a puddling-furnaceconstructed with my improvement. Fig. 2 is a longitudinal sectionalperspective representation of the puddlingfurnace shown in Fig. 1. Fig.3 is alongitudinal vertical section of the fire-chamber of thepuddling-furnace, showing the relative position of the sand, cinder, andfuel when the furnace is in operation.

In the several figures like letters of reference denote similar parts ofthe furnace.

The puddling-furnace represented in the drawings is of the ordinaryconstruction, of such furnaces as used in \Vestern Pennsylvania, so faras relates to the hearth B, in which the iron is puddled, and the stackor chimney O. The fire-chamber A is, however, differently constructedfrom what is usual. As ordinarily made, it is a rectangular chamber,with parallel vertical sides and open gratebars at bottom, which areplaced a little only below the bottom of the hearth in the puddlingchamber. These grate -bars, forming the bottom of the fire-chamber, areusually about two inches wide, thirty-six inches long, and placedparallel to each other, about two or three inches apart.

My fire-chamber (see Figs. 2 and 8) is constructed, in the usual manner,above the line a; x, (which is the usual level of the grate-bars.) Belowthe line so :0, I continue the fire-chamber down of fire-brick, butgradually contracting it by sloping its sides, as seen in Figs. 2 and 3,to a convenient depth-say about fifteen inches below the line so :11.Just below the line as x is a small opening, a, through the side orfront wall of the fire-chamber, designed to allow of the outflow of themelted cinder as it forms and rises above that level. Just above theopening a is the aperture 1') for the blastpipe, on either or both sidesof the fire-chamber, for the admission of air to the fire. It will bebetter to incline this opening for the blast downward, and insert atuyere to direct the current of air against the surface of the hotcinder, and to prevent the choking up of the blasthole by the influx ofthe melted cinder. The fire-chamber may be built upon an iron plate,

, c, to which is attached a hinged iron door, (I,

which shuts up against the opening in the bottom of the fire-chamber,which opening may be about twenty -four inches square. This opening isof the full size of the bottom of the firechamber. The hinged door d iskept closed in any convenient way, as by a bar, 0. (Seen in Figs. 2 and3.) A few inches above the bottom plate or hinged door, (I, is anothersmall opening, f, similar to a, which is designed for running out themelted cinder when it is desired to clean out the fire-chamber. Thehinged door d at bottom of the fire-chamber affords an opportunity forcleaning out the entire contents of the fire-chamber, and the door y inthe side is for the purpose of obtaining admission when any repairs arenecessary. The square opening h is the stock-hole,

through which the fuel is supplied to the furthe hinged door d is closedand fastened. A

layer of sand, 1', (about four inches deep,) is placed upon it insidethe furnace, extending up to the bottom of the opening f. This opening fis kept closed while the furnace is at work. The upper opening, a, isleft open. The sand forms a protection to the hinged door or bedplate(I, so that it will not burn out. On this layer of sand the fire isbuilt, and the blast is turned on through the tuyere or opening I). Whenthefire is welllighted,somehammer-slag or oxide of iron, or othersuitable flux, is thrown on the coals, which is repeated from time totime. This melts and runs down into the bosh or receptacle below theline as x. This oxide of iron serves as a flux to melt the substances inthe coal which form the cinder-such as silica, sulphate of iron, &c.-andthey also run down into the bosh. As the melted cinder thus forms in thebosh, the fuel rises (being of less specific gravity) until the bosh isfull of melted cinder to the bottom of the opening a, when the fuel andcinder occupy their proper relative positions. The cinder, as itaccumulates, runs out spontaneously through the opening a, and themelted cinder serves to keep the lower part of the fire fully ignitedand red-hot. The blast of air entering through the tuyere at b strikesthe surface of the melted cinder, and is heated, rises up through thehottest of the fire, and, uniting with the smoke at the top of the fuel,causes its combustion, thus effecting a great saving of fuel andincrease of heat. This is manifest in practice, from the fact that whilepuddling-furnaces of ordinary construction emit large volumes of smokewhen in operation, a furnace constructed with my improvement scarcelygives off any smoke, excepting at the moment when the stock-hole isopened to add fresh fuel, and the smoke thus caused ceases as soon asthe stock-hole is again closed. Another great ad vantage of admittingthe air in the manner described is that the oxygen, being consumed onuniting with the carbon, does not pass over into the puddling-chamber,as it usually does in puddling-furnaces of ordinary construction when itmingles with the iron ore and scrapiron used for fixing, and causes agreat waste by the formation of oxide of iron, so that my improvementeffects a saving of the cost of one-half of the fixing in apuddlingfurnace.

My improvement is applicable not only to jpuddling and boiling furnaces,as described,

down and run off in my furnace Without employing it, but not soreadily.- Neither isit absolutely necessary to retain the melted cinderin any quantity in the bottom or bosh of the fire-chamber; but it may,if preferred, be allowed to run off as rapidly as it accumulates. Thismay be effected by diminishing the depth of the bosh or the distancebetween the bottom of the fire-chamber and the point, of exit of thecinder, either by filling up the bosh with sand or building it with avery shallow bosh.

Having thus described my improvement in the fire-chamber of coal-burningfurnaces for puddling, boiling, or reheating iron, what I claim as myinvention, and desire to secure by Letters Patent, is

1. Constructing the fire-chamber of reverberatory furnaces for puddling,boiling, or reheating iron, in which coal is used as fuel, so as to format its base a contracted receptacle for the accumulation of the meltedcinder below the point where the blast of air is admitted, incombination with a close air-tight firechamber bottom, for the purposeof freeing the fuel of its incombustible particles by'keeping the cinderin a melted state so long as it remains in the fire-chamber, and thuspreventing the formation of clinker, as described.

2. Fluxing the clinker in the fire-chamber of a puddling, boiling, orreheating furnace constructed as above described by means of theintroduction with the fuel into the firechamb'er of oxide of iron orother suitable blast before it ascends through the mass offuel in thefire-chamber, and thus increase the intensity of combustion and consumethe smoke, as set forth.

In testimony whereof I, the said JACOB REEsE, have hereunto set my hand.

JACOB REESE.

\Vitnesses:

MARTIN G. CUSHING, A. S. NIcHoLsoN.

